This invention relates to fuel supply system for internal combustion engines and, more particularly, to dual fuel systems operable to supply two different fuels to an internal combustion engine.
It is known to provide dual fuel supply systems capable of selectively supplying a more expensive fuel, such as gasoline, to an internal combustion engine during starting, idle and low speed operations and a less expensive fuel, such as kerosene, during low and normal speed operations.
Prior dual fuel systems are disclosed in the following U.S. patents:
______________________________________ PATENTEE U.S. PAT. NO. ISSUE DATE ______________________________________ Bartholomew 2,616,404 Nov. 4, 1952 Meyer, et al 2,643,647 June 30, 1953 Anderson 2,664,871 Jan. 5, 1954 Boyce 4,056,087 Nov. 1, 1977 Etoh 4,085,720 April 25, 1978 Itoh, et al 4,090,484 May 23, 1978 Etoh 4,129,620 Dec. 12, 1978 ______________________________________
Attention is also directed to British Pat. No. 644,721, published Oct. 18, 1950. Attention is further directed to the Billingsley et al application Ser. No. 175,348, filed Aug. 4, 1980, now U.S. Pat. No. 4,375,795 and the Haman et al application Ser. No. 406,446, filed Aug. 9, 1982, now U.S. Pat. No. 4,462,346 both assigned to the assignee of the present application.